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Medians & Altitudes of Triangles. P, R, Rh,S 11. 25,65,65,90 P, R, Rh,S 12. 4 P, R, Rh,S 13. 10 P, R, Rh,S 14. 18, 72, 72 P, R, Rh,S 15. 13.5 R, S 16. 2 Rh , S 17. 32, 58, 58 Rh , S 18. 9 R, S 19. 1/2 Rh , S 10 25. 15 30 27. 60.
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Medians & Altitudes of Triangles
P, R, Rh,S 11. 25,65,65,90 • P, R, Rh,S 12. 4 • P, R, Rh,S 13. 10 • P, R, Rh,S 14. 18, 72, 72 • P, R, Rh,S 15. 13.5 • R, S 16. 2 • Rh, S 17. 32, 58, 58 • Rh, S 18. 9 • R, S 19. 1/2 • Rh, S • 10 25. 15 • 30 27. 60 HW answers p. 187
p. 188 # 28 B A Given: ABZY; ZY BX; 1 2 Prove: ABZY is a rhombus 1 2 3 X Y Z Statements Reasons • ABZY; ZY BX; 1 2 1. Given • BX BZ 2. Isosceles Triangle Them • ZY BZ 3. Substitution • ABZY is a rhombus 4. A parallelogram with congruent consecutive sides
p. 188 # 29 B A Given: ABZY; AY BX Prove:1 2; 1 3 1 2 3 X Y Z Statements Reasons • ABZY; AY BX 1. Given • AY BZ 2. Opp sides of a p-gram are • BX BZ 3. Substitution • 1 2 4. Isosceles Triangle Theorem • 3 2 5. // lines form corr. Angles • 1 3 6. Substitution
Trapezoid – a quadrilateral with exactly ONE pair of parallel sides.
Properties of a Trapezoid: Base angles bases : parallel sides : non-parallel sides legs : angles formed by a base and a leg. base angles base leg leg base
A Special Trapezoid… Isosceles W X Z Y Isosceles Trapezoid: A trapezoid with legs. congruent Theorem: Base angles of an isosceles trapezoid are . congruent If trap WXYZ has WZ XY, then W X and Y Z .
Median of a Trapezoid – a segment in a trapezoid that connects the two midpoints of the non-parallel sides. LO is the median of the trapezoid. J K L O N M JO @ ON KL @ LM O is the ______ of JN. L is the ______ of KM. midpoint midpoint
16 + 10 2 = 13 The length of the median of a trapezoid is the average of the lengths of the parallel sides. 16 13 10
4 12 7 19 10 26 15 20 15 20 10 25
7x+3 Algebra Connection 7(4) + 3 = 31 2(4) – 1 = 7 19 2x - 1
6x + 10 Algebra Connection 6(5) + 10 = 40 8(5) + 20 = 60 x + 45 5 + 45 = 50 8x + 20
Algebra Connections Practice HW p. 192 1-17, 21, 22, 23